[FFmpeg-devel] [PATCH 2/2] avcodec/dvbsubdec: Split best score computation out of loop in compute_default_clut()

Clément Bœsch u at pkh.me
Sun Oct 1 19:26:53 EEST 2017


On Sun, Oct 01, 2017 at 06:10:36PM +0200, Michael Niedermayer wrote:
> 3% faster
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/dvbsubdec.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/dvbsubdec.c b/libavcodec/dvbsubdec.c
> index 6a40f2376f..e60bf41936 100644
> --- a/libavcodec/dvbsubdec.c
> +++ b/libavcodec/dvbsubdec.c
> @@ -681,14 +681,17 @@ static void compute_default_clut(AVSubtitleRect *rect, int w, int h)
>                  int l_r = x+1<w ? L(+1, 0) : 1;
>                  int l_t = y     ? L(0, -1) : 1;
>                  int l_b = y+1<h ? L(0, +1) : 1;
> -                int score;
>                  if (l_m)
>                      continue;
>                  scoretab[v] += l_l + l_r + l_t + l_b;
> -                score = 1024LL*scoretab[v] / counttab[v];
> +            }
> +        }
> +        for (x = 0; x < 256; x++) {
> +            if (scoretab[x]) {
> +                int score = 1024LL*scoretab[x] / counttab[x];
>                  if (score > bestscore) {
>                      bestscore = score;
> -                    bestv = v;
> +                    bestv = x;
>                  }
>              }
>          }

OK

-- 
Clément B.
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